In the foregoing applications novel surgical scissor instruments are disclosed. The preferred embodiments of the instruments disclosed include a handpiece containing an ultrasonic transducer operative to convert electrical energy into ultrasonic longitudinal vibratory motion. Extending from the handpiece is an elongate portion including a fixed outer tubular member depending from the handpiece. An inner shaft is located in the fixed outer tubular member for reciprocating movement relative to the fixed outer tubular member. A proximal end portion of the inner shaft is operatively connected to the transducer for causing the inner shaft to longitudinally vibrate.
A first cutting member is fixedly mounted to the distal end of the inner shaft and extends from the distal end of the outer tubular member. Longitudinal vibratory motion generated by the transducer affects corresponding longitudinal vibratory motion of the first cutting member, via the inner shaft. A second cutting member is connected to the inner shaft and is pivotable between an open and closed position with respect to the vibrating first cutting member. A second shaft has a first end pivotally connected to the second cutting member for affecting pivotable movement of the second cutting member between the open and closed positions.
The present invention is directed to improvements in various types of surgical instruments. In accordance with the invention, a hollow shaft is provided which has a working piece, such as a cutting blade, at its distal end. In the case of the instrument being of the ultrasonic type, the proximal end of the hollow shaft receives mechanical energy from an ultrasonic transducer to vibrate the working piece. Such a transducer can be of the piezoelectric or magnetostrictive type. For the latter, a coil of wire receiving electrical energy of a predetermined frequency energizes a stack of laminations. An acoustically tuned connecting body converts the vibrations of the lamination stack into mechanical energy that is conveyed along the length of the shaft to the working piece at the distal end.
In the preferred embodiment, a member is mounted outside of the shaft which is movable relative to the shaft distal end working piece. In the case of the instrument being a scissors, the shaft distal end working piece is one blade and the movable member is the second blade. The movable member is actuated by a connecting element that extends through the inner passage of the hollow shaft and exits through an opening in the shaft to be attached to the movable member. In the case of the instrument being of the ultrasonic type, the movable member preferably is mounted at a nodal point of the mechanical energy that is transmitted along the length of the shaft and the exit opening for the connecting element preferably is also at a nodal point along the shaft. This minimizes the loss of energy to the working piece and also minimizes rubbing friction between the connecting element and the vibrating shaft at the opening.
The instrument has only a single shaft which can be of a very small diameter and no external shafts are needed for the movable member. The principles of the invention are adaptable both to ultrasonic and non-ultrasonic instruments.
It is therefore an object of the invention to provide improved surgical instruments in which a hollow shaft has a working piece at its distal end and a movable member cooperating with the working piece is actuated by a connecting element extending through the shaft.
Another object is to provide improved ultrasonic surgical instruments in which a hollow shaft vibrated by ultrasonic energy has a working piece at its distal end and a movable member, which is preferably mounted at a nodal point of the vibrating shaft, is actuated by a connecting element extending through an opening in the shaft, also preferably at a nodal point, and has a cooperating action with the shaft working piece.
A further object is to provide a surgical instrument having a hollow shaft housing a plurality of working pieces that can be selected for use by one or more connecting elements extending in the shaft inner passage.